The rationale for this renewal application is to continue our highly collaborative and multidisciplinary, inter- institutional program of mentored training for future scientists in pediatric transfusion medicine and hematology. Our objective is to address the barriers for the conduct of high quality and transformative research in pediatric transfusion medicine and hematology including: 1) lack of a robust infrastructure for research training and implementation; 2) shortage of mid-career and senior investigators to serve as research mentors; 3) need for multidisciplinary translational approaches to answer critical clinical questions; 4) lack of diversity among clinical and translational investigators. This program is focused on advancing clinical and translational scholarship on the diagnosis and clinical management of hematological, cardiovascular and pulmonary disorders, transfusion, cell therapy and transplantation. The design of the Pediatric Hematology and Transfusion Medicine Multidisciplinary Research Training Award (PHTMMRT) is focused on preparing trainees from diverse backgrounds for academic leadership and independently funded research careers. Each trainee in the program completes a Master's in Clinical and Translational Science (MsCTR) at the George Washington University (GWU) School of Medicine and Health Sciences or equivalent, and will devise, implement and complete a research project under the joint oversight of a multidisciplinary mentorship team. At the completion of the two- to three-year program, each trainee will have presented his/her data to at least one national research meeting, drafted and submitted one or more manuscripts suitable for external peer-reviewed publications, and for those in a three-year program, submitted an external grant application to the NIH or equivalent funding source. The program is overseen by two NIH-funded Principal Investigators with complementary clinical and research expertise, supported by nine faculty of Children's National and GWU, with four external mentors. All mentors are research scientists with expertise in coagulation, transfusion medicine, cell therapy, transplantation, vascular biology and genomic/proteomics. A Diversity Enhancement Officer will assist in the recruitment of minority, disabled or disadvantaged applicants, and women. Finally, an External Advisory Committee of four NIH-funded national leaders in transfusion medicine, transplantation and hematology with established career mentorship programs will offer annual feedback and guidance of the PHTMMRT program and the trainees' progress. The PHTMMRT program will leverage several of Children's National's multiple and pre-existing strengths with collaborating neighboring research institutions including the NIH, GWU and Howard University School of Medicine (HUSM). In summary, our multidisciplinary, inter-institutional mentors will train four to five future academic leaders in Pediatric Hematology/Transfusion Medicine including a focus on cell-based therapies for heart, lung and blood diseases.